U.S. patent number 6,243,005 [Application Number 09/368,285] was granted by the patent office on 2001-06-05 for self-locking seal.
This patent grant is currently assigned to Hi-F-Tek Ltd.. Invention is credited to Yehuda Armoni, Michael Auerbach, Yosef Haimovich.
United States Patent |
6,243,005 |
Haimovich , et al. |
June 5, 2001 |
Self-locking seal
Abstract
An electronic seal including a housing, alarm circuitry which
when actuated provides an alarm signal, a wire extending from the
housing and in electrical communication with the alarm circuitry, a
locking element which selectively lockingly engages the wire to the
housing, and a switch external to the housing in electrical
communication with the locking element which selectively unlocks
the locking element to release the wire. There is also provided an
electronic seal including a housing including alarm circuitry, the
alarm circuitry when actuated providing an alarm signal, a wire
extending from the housing and in electrical communication with the
alarm circuitry, the wire being attached at a first point and at a
second point thereof to the housing, a portion of the wire between
the first and second points, called a tying portion, being suitable
for tying an object, wherein tampering with the tying portion
actuates the alarm circuitry, and an adjustment device for
adjusting a length of the tying portion.
Inventors: |
Haimovich; Yosef (Rishon le
Zion, IL), Armoni; Yehuda (Reut, IL),
Auerbach; Michael (Maccabim, IL) |
Assignee: |
Hi-F-Tek Ltd. (Or-Yehuda,
IL)
|
Family
ID: |
26323688 |
Appl.
No.: |
09/368,285 |
Filed: |
August 3, 1999 |
Foreign Application Priority Data
|
|
|
|
|
Aug 3, 1998 [IL] |
|
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125644 |
Nov 5, 1998 [IL] |
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126928 |
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Current U.S.
Class: |
340/427; 340/432;
340/568.1; 340/571 |
Current CPC
Class: |
G09F
3/0329 (20130101); G09F 3/0352 (20130101); G09F
3/0394 (20130101) |
Current International
Class: |
G09F
3/03 (20060101); B60R 025/10 () |
Field of
Search: |
;340/540,542,545.1,545.2,545.7,546,548,568.1,568.2,568.3,568.4,568.7,571,572.9
;242/287,421.5 ;324/509 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Trieu; Van T.
Attorney, Agent or Firm: Abelman, Frayne & Schwab
Claims
What is claimed is:
1. An electronic seal comprising:
a portable housing;
alarm circuitry which when actuated provides an alarm signal;
a wire extending from said housing and in electrical communication
with said alarm circuitry, whereby tampering with said wire causes
actuation of said alarm circuitry;
a locking element which selectively lockingly engages said wire to
said housing; and
a coded switch in electrical communication with said locking
element which selectively unlocks said locking element to release
said wire and prevent actuation of said alarm circuitry.
2. The electronic seal according to claim 1, wherein said alarm
circuitry detects an open circuit in a circuit comprising said
alarm circuitry and at least one of said wire and said locking
element.
3. The electronic seal according to claim 1, wherein said switch is
mounted on an external surface of said housing.
4. The electronic seal according to claim 1, wherein said switch
comprises a remote control device.
5. The electronic seal according to claim 4, wherein said remote
control device communicates with said seal by means of encrypted
communication.
6. The method according to claim 5, wherein said encrypted
communication comprises a mutual zero-knowledge interaction
authentication session.
7. The electronic seal according to claim 4, wherein said remote
control device comprises a computer terminal in wireless
communication with said housing.
8. The electronic seal according to claim 1, wherein said locking
element comprises a solenoid which selectively lockingly engages
said wire.
9. The electronic seal according to claim 8, wherein said solenoid
comprises a tongue which selectively protrudes from said solenoid
and fixedly clamps said wire.
10. The electronic seal according to claim 8, wherein said wire is
connected to an electrical jack and said solenoid comprises a
tongue which selectively protrudes from said solenoid and fixedly
clamps said jack.
11. The electronic seal according to claim 8, wherein said wire is
wound around a bobbin and said solenoid selectively fixedly clamps
said bobbin, thereby also clamping said wire.
12. The electronic seal according to claim 1, wherein said locking
element is selected from the group consisting of an electric motor,
a piezoelectric crystal actuator, a pneumatic actuator, a hydraulic
actuator, and a spring-actuated actuator.
13. The electronic seal according to claim 1, wherein said wire
which extends from said housing is attached at a first point and at
a second point thereof to said housing, and a portion of said wire
between said first and second points, called a tying portion, is
suitable for tying an object, wherein tampering with said wire
actuates said alarm circuitry, and the seal further comprises an
adjustment device for adjusting a length of said tying portion.
14. An electronic seal comprising:
a housing comprising alarm circuitry, said alarm circuitry, when
actuated providing an alarm signal;
a wire extending from said housing and in electrical communication
with said alarm circuitry, whereby tampering with said wire causes
actuation of said alarm circuitry, said wire being attached at a
first point and at a second point thereof to said housing, a
portion of said wire between said first and second points, called a
tying portion, being suitable for tying an object, wherein
tampering with said wire actuates said alarm circuitry;
a locking element which selectively lockingly engages said wire to
said housing; and
a coded switch in electrical communication with said locking
element which selectively unlocks said locking element to release
said wire and prevent actuation of said alarm circuitry; and
an adjustment device for adjusting a length of said typing
portion.
15. The electronic seal according to claim 14, wherein said
adjustment device comprises a yoke for wrapping therearound said
tying portion.
16. The electronic seal according to claim 15, wherein an
electrical element is disposed through said yoke, said electrical
element being in electrical communication with said alarm
circuitry, wherein a change in an electrical parameter of said
electrical element is communicated to said alarm circuitry for
actuation thereof.
17. The electronic seal according to claim 14, wherein said
adjustment device comprises a tightening device to which said wire
is attached, said tightening device permitting said wire to be
drawn out of and to be pulled into said housing, and substantially
fixing said wire at said second point thereof.
18. The electronic seal according to claim 17, wherein said
tightening device comprises a locking element which selectively
lockingly engages said wire.
19. The electronic seal according to claim 17, wherein said
tightening device comprises a bobbin around which said wire is
wound and a locking element which selectively lockingly engages
said bobbin.
20. The electronic seal according to claim 17, and further
comprising a measuring device that measures a change in angular
position of said bobbin, said measuring device using said change to
actuate said alarm circuitry.
21. The electronic seal according to claim 14, wherein a portion of
said wire forms part of a Wheatstone bridge in electrical
communication with said alarm circuitry for measuring changes in
electrical resistance of said wire.
22. The electronic seal according to claim 14, wherein said first
point is attached to an electrical connector in electrical
communication with said alarm circuitry.
Description
FIELD OF THE INVENTION
The present invention relates to electronic seals generally, and
particularly to a self-locking electronic seal.
BACKGROUND OF THE INVENTION
Electronic tags are known that can be attached to an object and
monitored, sensed, or interrogated for purposes of preventing theft
of or tampering with the object. For example, applicant/assignee's
U.S. patent application Ser. No. 08/815,389, the disclosure of
which is incorporated herein by reference, describes a
battery-operated electronic seal that, when tampered with,
communicates via a transceiver to a detection system for providing
an alarm signal or other indication, and thereby detect the
tampering and/or removal of the seal from an object sealed or
tagged therewith. One of the electronic seals described in U.S.
patent application Ser. No. 08/815,389 employs resistive wires
which when tampered with provide an indication of such
tampering.
SUMMARY OF THE INVENTION
The present invention seeks to provide improvements to the
electronic seal described in U.S. patent application Ser. No.
08/815,389 which employs resistive wires. In the seal of the
present invention, there is a locking element which selectively
lockingly engages a wire, and the locking element can be unlocked
only by means of an external switch.
There is thus provided in accordance with a preferred embodiment of
the present invention an electronic seal including a housing, alarm
circuitry which when actuated provides an alarm signal, a wire
extending from the housing and in electrical communication with the
alarm circuitry, a locking element which selectively lockingly
engages the wire to the housing, and a switch external to the
housing in electrical communication with the locking element which
selectively unlocks the locking element to release the wire.
In accordance with a preferred embodiment of the present invention
the switch is mounted on an external surface of the housing.
Further in accordance with a preferred embodiment of the present
invention the switch includes a coded switch.
Still further in accordance with a preferred embodiment of the
present invention the external switch includes a remote control
device.
Additionally in accordance with a preferred embodiment of the
present invention the external switch includes a computer terminal
in wireless communication with the housing.
In accordance with a preferred embodiment of the present invention
the locking element includes a solenoid which selectively lockingly
engages the wire.
Further in accordance with a preferred embodiment of the present
invention the solenoid includes a tongue which selectively
protrudes from the solenoid and fixedly clamps the wire.
Still further in accordance with a preferred embodiment of the
present invention the wire is connected to an electrical jack and
the solenoid includes a tongue which selectively protrudes from the
solenoid and fixedly clamps the jack.
Additionally in accordance with a preferred embodiment of the
present invention the wire is wound around a bobbin and the
solenoid selectively fixedly clamps the bobbin, thereby also
clamping the wire.
There is also provided in accordance with a preferred embodiment of
the present invention an electronic seal including a housing
including alarm circuitry, the alarm circuitry when actuated
providing an alarm signal, a wire extending from the housing and in
electrical communication with the alarm circuitry, the wire being
attached at a first point and at a second point thereof to the
housing, a portion of the wire between the first and second points,
called a tying portion, being suitable for tying an object, wherein
tampering with the tying portion actuates the alarm circuitry, and
an adjustment device for adjusting a length of the tying
portion.
In accordance with a preferred embodiment of the present invention
the adjustment device includes a yoke for wrapping therearound the
tying, portion.
Further in accordance with a preferred embodiment of the present
invention an electrical element is disposed through the yoke, the
electrically element being in electrical communication with the
alarm circuitry, wherein a change in an electrical parameter of the
electrical element is communicated to the alarm circuitry for
actuation thereof
Still further the adjustment device includes a tightening device to
which the wire is attached, the tightening device permitting the
wire to be drawn out of and to be pulled into the housing, and
substantially fixing the wire at the second point thereof
Preferably the tightening device includes a locking element which
selectively lockingly engages the wire.
Additionally in accordance with a preferred embodiment of the
present invention the tightening device includes a bobbin around
which the wire is wound and a locking element which selectively
lockingly engages the bobbin.
In accordance with a preferred embodiment of the present invention
a portion of the wire forms part of a Wheatstone bridge, in
electrical communication with the alarm circuitry, for measuring
changes in electrical resistance of the wire.
Additionally in accordance with a preferred embodiment of the
present invention the first point is attached to an electrical
connector in electrical communication with the alarm circuitry.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood and appreciated more fully
from the following detailed description, taken in conjunction with
the drawings in which:
FIG. 1 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with a preferred embodiment
of the present invention with an external switch for unlocking a
locking element which selectively lockingly engages a wire,
FIG. 2 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with another preferred
embodiment of the present invention;
FIG. 3 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with yet another preferred
embodiment of the present invention;
FIG. 4 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with still another
preferred embodiment of the present invention and comprising a
bobbin around which the wire is wound;
FIG. 5 is a simplified block diagram of illustration of the
electronic seal of FIG. 1;
FIG. 6 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with another preferred
embodiment of the present invention and comprising a yoke for
wrapping therearound a wire; and
FIG. 7 is a simplified pictorial illustration of an electronic seal
constructed and operative in accordance with yet another preferred
embodiment of the present invention and comprising an extender yoke
for wrapping therearound a wire.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
Reference is now made to FIG. 1 which illustrates an electronic
seal 10 constructed and operative in accordance with a preferred
embodiment of the present invention.
Electronic seal 10 preferably includes a housing 12 including alarm
circuitry 14, which when actuated provides an alarm signal. Alarm
circuitry 14 is preferably constructed in accordance with the
circuitry disclosed in U.S. patent application Ser. No.
08/815,389.
A wire 16 extends from housing 12 and is in electrical
communication with alarm circuitry 14. Wire 16 is attached at a
first point 18 and, optionally at a second point 20 thereof, to
housing 12. In the illustrated embodiment, first and second points
18 and 20 are electrical sockets mounted on an external surface of
housing 12. For convenience, a jack 19 may be attached to one end
of wire 16 which fixedly mates with one of these electrical
sockets. Tampering with any portion of wire 16 actuates alarm
circuitry 14. For example, as taught in U.S. patent application
Ser. No. 08/815,389, wire 16 may be a frangible element, such as a
shielded wire, which when broken provides an output indication of
tampering with seal 10. Alternatively, wire 16 may comprise
electrically resistive wire, and tampering with wire 16 causes a
change in electrical resistance of the wire, which change is
communicated to alarm circuitry 14 for actuation thereof.
Electronic seal 10 preferably includes a locking element 11 which
selectively lockingly engages wire 16 to housing 12. In the
embodiment of FIG. 1, locking element 11 comprises a solenoid 17
which selectively lockingly engages wire 16. Solenoid 17 preferably
includes a tongue 33 (shown generally U-shaped, but may be any
other arbitrary shape) which selectively protrudes from solenoid 17
and fixedly clamps jack 19. As shown in FIG. 1, two jacks 19 may be
provided each of which is clamped by a corresponding solenoid 7. A
switch 15, mounted externally on housing 12, and in electrical
communication with locking element 11, selectively unlocks locking
element 11 in order to release wire 16. Switch 15 preferably is a
coded switch that includes a plurality of keys or buttons 23 for
entering a code for unlocking locking element 11. A display 21 may
be provided on housing 12 for displaying signals, characters,
numeral or letters, for example, related to the code or upon which
the code may be based.
Wire 16 is shown in FIG. 1 as being releasably attached at second
point 20 to housing 12. Alternatively, wire 16 may be permanently
attached at second point 20 to housing 12. It is also appreciated
that circuitry 14 may alternatively be remotely located from
electronic seal 10 and in communication therewith.
Referring additionally to FIG. 5, it is seen that instead of a
solenoid, other actuation apparatus may be used, such as, but not
limited to, an electric motor, piezoelectric crystal actuator,
pneumatic actuator, hydraulic actuator, or spring-actuated
actuator.
Reference is now made to FIG. 2 which illustrates electronic seal
10 actuated by a different kind of switch 27 in accordance with
another preferred embodiment of the present invention. In this
embodiment, the switch 27 may include a remote control device 29 in
wireless communication with a transceiver 31 connected to circuitry
14 and solenoids 17. Transceiver 31 preferably not only receives a
signal from remote control device 29, but also wirelessly transmits
an alarm signal generated by alarm circuitry 14. Alternatively, the
remote control device or switch 27 may include a computer terminal
41 and keyboard 43 in wireless communication via a transmitter 45
with transceiver 31. In order to enhance security, the
communication may be encrypted. For example, well known encryption
algorithms, such as RC-5, DES or DVB, may be employed. To provide
an even greater level of trust, mutual zero-knowledge interaction
authentication sessions between the remote control device and seal
10 may be held, such as the so-called Fiat-Shamir authentication
methods taught in U.S. Pat. No. 4,748,668 to Shamir and Fiat, the
disclosure of which is incorporated herein by reference.
Reference is now made to FIG. 3 which illustrates an electronic
seal 30 constructed and operative in accordance with yet another
preferred embodiment of the present invention. Electronic seal 30
is preferably similar in construction to seal 10, with like
elements being designated by like numerals. Electronic seal 30
differs from seal 10 in that seal 30 includes an adjustment device
32 which comprises a tightening device 34 to which wire 16 is
attached. Tightening device 34 preferably includes a conduit 36
through which wire 16 can be drawn out of and pulled into housing
12 (in the directions generally indicated by arrows 38), and a
locking element 40 which selectively lockingly engages wire 16 so
as to substantially fix wire 16 at a second point 42 thereof
Locking element 40 is preferably in electrical communication with
alarm circuitry 14 and comprises a solenoid 49 which clamps down on
wire 16, for example. Locking element 40 is also preferably in
electrical communication with wire 16, so that any attempt to
disconnect or detach wire 16 from locking element 40 will be sensed
by alarm circuitry 14. Thus, locking element 40 and wire 16 serve
as an electronic lock. In this embodiment, wire 16 is preferably,
but not necessarily, an unshielded resistive wire whose resistance
can be measured from the outside, such as a conductive elastomer,
e.g., an elastomeric RF gasket material.
In accordance with a preferred embodiment of the present intention,
a portion of wire 16 can be used to form part of a Wheatstone
bridge 37, in electrical communication with alarm circuitry 14, for
measuring changes in electrical resistance of wire 16.
Reference is now made to FIG. 4 which illustrates an electronic
seal 50 constructed and operative in accordance with yet another
preferred embodiment of the present invention. Electronic seal 50
is preferably similar in construction to seal 10, with like
elements being designated by like numerals. Electronic seal 50
differs from seal 10 in that seal 50 includes an adjustment device
52 which comprises a tightening device 54 to which wire 16 is
attached. Tightening device 54 preferably includes a bobbin 56
around which wire 16 is wound and a locking element 58, preferably
a solenoid 61, which selectively lockingly engages bobbin 56.
Bobbin 56 may include a gear, in which case solenoid 61 preferably
includes a tongue 63 which engages the teeth of the gear so as to
substantially fix wire 16 at a second point 59 thereof It is
appreciated that locking element 58 may be manually or
automatically locked and unlocked, as well as by remote control.
Preferably the angular position and/or rotation of bobbin 56 is
measured by a measuring device 60, such as an encoder. The initial
angular position of bobbin 56, i.e., after sealing the object with
seal 50, is fed to the alarm circuitry 14. Any angular change in
the position of bobbin 56 is then used as a criterion for detection
of tampering.
Further embodiments of the invention will now be described which
are particularly useful as electronic seals for tying sacks and the
like.
It is very common to close sacks, bags and the like by tying them
with rope, cord, string, wire, etc., and then seal the tie with
some type of inspector's seal which provides an indication of
tampering with the seal. Such seals are generally mechanical in
nature, such as the familiar lead seal lug on electrical meters, or
quality assurance decals on the lids of electronic equipment.
However, electronic seals have not been used in the art for sealing
sacks. Although one of the electronic seals described in U.S.
patent application Ser. No. 08/815,389 employs resistive wires
which when tampered with provide an indication of such tampering,
nevertheless these wires are not readily applicable for providing a
tampering indication when tied to a sack. One of the reasons is
that the wires have a fixed length and after tying there is a
portion of the wires which is inevitably left loose or dangling. If
any portion of the wire is tampered with, dangling or not, an alarm
will be sounded. However, in general, the alarm will be indicative
of an actual attempt to break into the sack only if the part of the
wire that is wrapped around and actually sealing the sack is
tampered with. On the other hand, tampering with the dangling part
is not necessarily indicative of an attempt to pilfer or tamper
with the contents of the sack, and thus would constitute a false
alarm.
Reference is now made to FIG. 6 which illustrates an electronic
seal 10' constructed and operative in accordance with a preferred
embodiment of the present invention, and which is particularly
useful as a seal for tying and securing, a sack and the like.
Electronic seal 10' is preferably similar in construction to seal
10, with like elements being designated by like numerals. In
electronic seal 10', a tying portion 22 of wire 16 is defined
between first and second points 18 and 20 which is suitable for
tying an object, such as a sack or hasp, for example. Tampering
with any portion of wire 16 actuates alarm circuitry 14, as
described hereinabove.
In order not to have an unwanted dangling portion of wire 16 after
tying the object, an adjustment device 24 is provided for adjusting
a length of tying portion 22. In the embodiment of FIG. 6,
adjustment device 24 comprises a yoke 26 for wrapping, therearound
tying portion 22. Typically a user ties an object with wire 16,
jack 19 being the tree end of wire 16 during tying, and wraps any
extra wire around yoke 26. Thereafter, jack 19 is fixedly connected
to housing 12 at first point 18, and seal 10 is ready for
monitoring any tampering with the object. An electrical element 28,
such as an electrically resistive element or a conductive wire, is
disposed through yoke 26, electrical element 28 being in electrical
communication with alarm circuitry 14. Tampering with yoke 26, or
with the windings of wire 16 therearound, causes a change in
electrical resistance, capacitance or any other electrical
parameter, of electrical element 28, which change is communicated
to alarm circuitry 14 for actuation thereof
Reference is now made to FIG. 7 which illustrates an alternative
version of seal 10' wherein yoke 26 is replaced by an extender yoke
89. In this embodiment, first and second points 18 and 20 are
electrical connectors mounted on an external surface of extender
yoke 89. In this embodiment, electrical element 28 is routed
through the entire inner structure of extender yoke 89. Except for
the aforementioned differences, the embodiment of FIG. 7 operates
identically to the embodiment of FIG. 6.
It is noted that the embodiments of FIGS. 1 and 2, if provided with
a sufficient length of wire 16 between first and second points 18
and 20, can be used to tie and secure sacks and the like, although
these embodiments lack an adjustment device.
However, the embodiments of FIGS. 3 and 4 can readily be used to
tie and secure sacks and the like, wherein the adjustment device 32
and 52 are provided which comprise tightening devices 34 and 54,
respectively, as described hereinabove.
It will be appreciated by persons skilled in the art that the
present invention is not limited by what has been particularly
shown and described hereinabove. Rather the scope of the present
invention includes both combinations and subcombinations of the
features described hereinabove as well as modifications and
variations thereof which would occur to a person of skill in the
art upon reading the foregoing description and which are not in the
prior art.
* * * * *